The collapse-vulnerability analysis based on collapse probability is the most reasonable method to evaluate the collapse resistant capacity of structures. However, currently collapse probability analysis is mostly based on incremental dynamic analysis (IDA), which is difficult to be directly used for engineering design due to relatively heavy workload and complicated procedure. Therefore, it is necessary to develop a new method, which is convenient for engineering application. In this paper, 18 RC frames are analyzed respectively by using pushover analysis and IDA. Then, the correlation between the results of pushover and those of IDA are studied. The results show that there are fairly good correlated relations between the collapse margin ratio (CMR), the collapse probability under maximal considered earthquake (MCE) and the displacement margin ratio from pushover analysis. Based on these relations, the design displacement margin ratio of pushover analysis to meet the requirement of the collapse probability under MCE is recommended. Nine additional RC frames are used to validate the proposed displacement margin ratio, which shows this method is easy to use and can provide reference for engineering design of regular multistory RC frame.